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EP0530534B1 - Lining for a direct-current arc furnace - Google Patents

Lining for a direct-current arc furnace Download PDF

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Publication number
EP0530534B1
EP0530534B1 EP92113481A EP92113481A EP0530534B1 EP 0530534 B1 EP0530534 B1 EP 0530534B1 EP 92113481 A EP92113481 A EP 92113481A EP 92113481 A EP92113481 A EP 92113481A EP 0530534 B1 EP0530534 B1 EP 0530534B1
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EP
European Patent Office
Prior art keywords
lining
furnace
area
electrically conductive
brick lining
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP92113481A
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German (de)
French (fr)
Other versions
EP0530534A1 (en
Inventor
Dane Meredith
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Primetals Technologies Austria GmbH
Original Assignee
Voest Alpine Industrienlagenbau GmbH
Deutsche Voest Alpine Industrieanlagenbau GmbH
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Publication date
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Publication of EP0530534A1 publication Critical patent/EP0530534A1/en
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Publication of EP0530534B1 publication Critical patent/EP0530534B1/en
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Classifications

    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
    • C21C5/52—Manufacture of steel in electric furnaces
    • C21C5/5229—Manufacture of steel in electric furnaces in a direct current [DC] electric arc furnace
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B7/00—Heating by electric discharge
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27B—FURNACES, KILNS, OVENS OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
    • F27B3/00—Hearth-type furnaces, e.g. of reverberatory type; Electric arc furnaces ; Tank furnaces
    • F27B3/08—Hearth-type furnaces, e.g. of reverberatory type; Electric arc furnaces ; Tank furnaces heated electrically, with or without any other source of heat
    • F27B3/085—Arc furnaces
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D11/00—Arrangement of elements for electric heating in or on furnaces
    • F27D11/08—Heating by electric discharge, e.g. arc discharge
    • F27D11/10—Disposition of electrodes
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B7/00—Heating by electric discharge
    • H05B7/02—Details
    • H05B7/06—Electrodes
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27B—FURNACES, KILNS, OVENS OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
    • F27B3/00—Hearth-type furnaces, e.g. of reverberatory type; Electric arc furnaces ; Tank furnaces
    • F27B3/10—Details, accessories or equipment, e.g. dust-collectors, specially adapted for hearth-type furnaces
    • F27B3/12—Working chambers or casings; Supports therefor
    • F27B2003/125—Hearths
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P10/00—Technologies related to metal processing
    • Y02P10/20—Recycling

Definitions

  • the invention relates to a lining for a direct current arc furnace according to the preamble of claim 1.
  • a direct current arc furnace is known from EP-A-0 422 406, in which the area receiving the melt consists of an electrically conductive refractory lining.
  • a cylindrical current conductor in the form of a copper ring is placed around this electrically conductive lining. Both, the conductive lining and the copper ring, together form the anode of the DC arc furnace.
  • the lining consists of several layers.
  • the layer that is in direct contact with the molten metal is formed from an electrically conductive, wear-resistant and fire-resistant material.
  • a layer of electrically conductive ramming compound is applied to the layer, which is in the form of a lining, for the purpose of compensating for unevenness.
  • This part of the lining should e.g. are made of carbon magnesite.
  • the thickness of the layer increases towards the outer edge and corresponds to the height of the copper ring, so that a favorable current transfer is ensured.
  • This layer is followed by a layer of electrically insulating refractory bricks, which fills the entire floor area of the furnace and ensures thermal insulation.
  • the electrical conductivity of the layer facing the molten bath and the bath agitation associated with it brings about a relatively uniform temperature distribution in the melt.
  • the carbon content of the carbon-magnesite stones can cause unwanted carburization of the steel melt when melting steel with a targeted low carbon content. Does it still come from melting errors, e.g. insufficient sump or mechanical effects of the feed material or top electrode, for damage to the layer facing the melt, so that the molten bath comes into direct contact with the graphite stones, these can dissolve, and the lining can be damaged so severely that extensive repair is required. In extreme cases, a melt bath breakthrough can occur through the hearth.
  • the electrically conductive refractory lining (ff lining) and the ring-shaped part of the lining, which consists of graphite stones, still ensure the current flow between the anode and the melt and ensure appropriate contact with the melting material, even during a cold start.
  • flushing devices such as they are used to homogenize the melt (eg with nitrogen or argon), are embedded in a mold in the middle of the hearth in the ramming mass.
  • these devices should also consist of non-conductive refractory material. The introduction of these homogenizing agents in the middle of the melting bath has a particularly favorable effect on their effect.
  • FIG. 1 shows a longitudinal section through the direct-current arc furnace according to the invention.
  • the arc furnace has an annular copper conductor 1, which forms part of the anode.
  • the cathode 2 is located centrally above the melt.
  • a fireproof insulating lining 7 is provided on the base part, which is preferably made of steel.
  • An annular part of the lining, which consists of graphite stones 3, is provided directly on the current conductor 1, which is designed as a copper ring, in a direct electrically conductive connection with the current conductor 1.
  • Another part of the Brick lining which consists of electrically conductive ff material 4. Both areas are interlinked.
  • the area of the brickwork, which consists of electrically conductive ff material 4 is also designed in a ring. This area is preferably made of carbon-magnesite stones.
  • a ramming mass 5 which preferably consists mainly of magnesite, is introduced.
  • the electrically conductive ff-lining 4 in the direction of the central hearth area, which is formed by the monolithic ramming mass 5, there is an intimate connection of the two areas.
  • insulating stones can be inserted as a transition, which improve the connection due to their thermal behavior. In connection with the sintering of the magnesite used as ramming mass, the penetration of steel in this critical transition area is prevented.
  • the lower refractory insulating lining 7 can be dispensed with in the lower floor area, where the monolithic ramming mass is arranged.
  • the extent of the central region of the hearth, which is formed by a monolithic ramming mass 5 is 2 m in diameter, but should fill at least 20% of the total outer diameter.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Plasma & Fusion (AREA)
  • Physics & Mathematics (AREA)
  • Manufacturing & Machinery (AREA)
  • Organic Chemistry (AREA)
  • Metallurgy (AREA)
  • Materials Engineering (AREA)
  • Vertical, Hearth, Or Arc Furnaces (AREA)
  • Furnace Details (AREA)
  • Furnace Housings, Linings, Walls, And Ceilings (AREA)
  • Discharge Heating (AREA)
  • Physical Vapour Deposition (AREA)

Abstract

A lining for a direct-current electric-arc furnace, in which at least part of that regions of said furnace which receives the melt is provided on the inside with an electrically conductive, refractory brick lining and a ring-shaped current conductor, on its outside, constitutes the opposite pole to the upper electrode centrally extending into said surface. The entire bottom area is covered with a refractory, insulating brick lining and a brick lining of graphite bricks is applied onto that brick lining in the radially outer wall region of the furnace. Located adjacent thereto in radially inward manner is an annular zone, comprising an electrically conductive, refractory brick lining. The central bottom area above said insulating brick lining is consittuted by a monolithic ramming mass. Furthermore, the material of the wall of said furnace above said brick lining of graphite bricks largely corresponds to that of said insulating brick lining at the hearth bottom.

Description

Die Erfindung betrifft eine Ausmauerung für einen Gleichstrom-Lichtbogenofen nach dem Oberbegriff des Anspruches 1.The invention relates to a lining for a direct current arc furnace according to the preamble of claim 1.

Aus der EP-A- 0 422 406 ist ein Gleichstrom-Lichtbogenofen bekannt, bei dem der die Schmelze aufnehmende Bereich aus einer elektrisch leitenden Feuerfest-Ausmauerung besteht. Um diese elektrisch leitende Ausmauerung ist ein zylinderförmiger Stromleiter in Form eines Kupferringes herumgelegt. Beide, die leitende Ausmauerung und der Kupferring, bilden gemeinsam die Anode des Gleichstrom-Lichtbogenofens.A direct current arc furnace is known from EP-A-0 422 406, in which the area receiving the melt consists of an electrically conductive refractory lining. A cylindrical current conductor in the form of a copper ring is placed around this electrically conductive lining. Both, the conductive lining and the copper ring, together form the anode of the DC arc furnace.

Die Ausmauerung besteht aus mehreren Schichten. Die Schicht, die mit der Metallschmelze in direkter Berührung steht, ist aus einem elektrisch leitenden verschleiß- und feuerfesten Material gebildet. Auf der Schicht, die als Ausmauerung vorliegt, wird zum Zwecke des Ausgleiches von Unebenheiten eine Schicht aus elektrisch leitender Stampfmasse aufgetragen. Dieser Teil der Ausmauerung soll z.B. aus Karbon-Magnesit bestehen.The lining consists of several layers. The layer that is in direct contact with the molten metal is formed from an electrically conductive, wear-resistant and fire-resistant material. A layer of electrically conductive ramming compound is applied to the layer, which is in the form of a lining, for the purpose of compensating for unevenness. This part of the lining should e.g. are made of carbon magnesite.

Unterhalb dieser Schicht ist eine Schicht aus Graphitsteinen, die eine wesentlich höhere elektrische Leitfähigkeit besitzen, angeordnet. Die Stärke der Schicht vergrößert sich zum Außenrand und entspricht dort der Höhe des Kupferringes, so daß ein günstiger Stromübergang gewährleistet ist.A layer of graphite stones, which have a significantly higher electrical conductivity, is arranged below this layer. The thickness of the layer increases towards the outer edge and corresponds to the height of the copper ring, so that a favorable current transfer is ensured.

An diese Schicht schließt sich eine Schicht aus elektrisch isolierenden feuerfesten Steinen an, die den gesamten Bodenbereich des Ofens ausfüllt und eine Wärmeisolierung gewährleistet.This layer is followed by a layer of electrically insulating refractory bricks, which fills the entire floor area of the furnace and ensures thermal insulation.

Die elektrische Leitfähigkeit der dem Schmelzbad zugewandten Schicht und die damit verbundene Badrührung bewirkt eine relativ gleichförmige Temperaturverteilung im Schmelzgut. Durch den Kohlenstoffgehalt der Karbon-Magnesit-Steine kann es beim Schmelzen von Stahl mit gezielt niedrigem Kohlenstoffgehalt jedoch zur ungewollten Aufkohlung der Stahlschmelze kommen. Kommt es weiterhin durch Fehler beim Schmelzen, z.B. ungenügender Sumpf oder mechanische Einwirkungen von Einsatzmaterial oder Oberelektrode, zur Beschädigung der der Schmelze zugewandten Schicht, so daß das Schmelzbad in direkter Berührung an die Graphitsteine gelangt, so können diese in Lösung gehen, und die Ausmauerung kann so stark beschädigt werden, daß eine umfangreiche Reparatur erforderlich wird. Im Extremfall kann ein Schmelzbaddurchbruch durch den Herd erfolgen.The electrical conductivity of the layer facing the molten bath and the bath agitation associated with it brings about a relatively uniform temperature distribution in the melt. However, the carbon content of the carbon-magnesite stones can cause unwanted carburization of the steel melt when melting steel with a targeted low carbon content. Does it still come from melting errors, e.g. insufficient sump or mechanical effects of the feed material or top electrode, for damage to the layer facing the melt, so that the molten bath comes into direct contact with the graphite stones, these can dissolve, and the lining can be damaged so severely that extensive repair is required. In extreme cases, a melt bath breakthrough can occur through the hearth.

Hier setzt die Erfindung ein, deren Aufgabe es ist, den Herdbereich eines Gleichstrom-Lichtbogenofens so auszuführen, daß seine Verschleißfestigkeit erhöht und das Eindringen von Kohlenstoff insbesondere aus dem mittleren Bereich des Herdes in die Schmelze weitestgehend verhindert wird.This is where the invention comes in, the task of which is to design the range of a direct-current arc furnace in such a way that its wear resistance is increased and the penetration of carbon, in particular from the central region of the range, into the melt is largely prevented.

Erfindungsgemäß wird diese Aufgabe durch die im Kennzeichen des Anspruches 1 genannten Merkmale gelöst.According to the invention, this object is achieved by the features mentioned in the characterizing part of claim 1.

Vorteilhafte Weiterbildungen und Ausführungsformen beinhalten die Merkmale der abhängigen Ansprüche.Advantageous further developments and embodiments contain the features of the dependent claims.

Dadurch, daß zumindest der mittlere Herdbereich, der durch eine monolithische Stampfmasse, die überwiegend aus Magnesit besteht, gebildet wird, das bei Erwärmung durch die Schmelze einen Sinterungsvorgang durchläuft, entsteht in diesem Bereich eine hochverschleißfeste Masse, die nicht elektrisch leitend ist und auch keine elektrischen Leiter enthält.The fact that at least the middle range, which is formed by a monolithic ramming mass, which mainly consists of magnesite, which undergoes a sintering process when heated by the melt, creates a highly wear-resistant mass in this area, which is not electrically conductive and also no electrical Contains ladder.

Die elektrisch leitende feuerfeste Ausmauerung (ff-Ausmauerung) und der ringförmige Teil der Ausmauerung, der aus Graphitsteinen besteht, sichern nach wie vor den Stromfluß zwischen Anode und Schmelze und gewährleisten einen entsprechenden Kontakt mit dem Schmelzgut, auch beim Kaltstart.The electrically conductive refractory lining (ff lining) and the ring-shaped part of the lining, which consists of graphite stones, still ensure the current flow between the anode and the melt and ensure appropriate contact with the melting material, even during a cold start.

Durch die Sinterung der aus Magnesit bestehenden Stampfmasse und durch den verzahnten Übergang mit der elektrisch leitenden ff-Ausmauerung, die aus Karbon-Magnesit besteht, wird die Penetration von Stahl besonders im Übergang zwischen den beiden Bereichen verhindert.The sintering of the ramming mass consisting of magnesite and the toothed transition with the electrically conductive ff-lining, which consists of carbon-magnesite, prevents the penetration of steel, especially in the transition between the two areas.

Sollten trotz der höheren Verschleißfestigkeit doch Reparaturen des Bodens erforderlich sein, so ist eine Ausbesserung bzw. Auswechslung der Stampfmasse im zentralen Bodenbereich wesentlich unaufwendiger als eine Ausbesserung einer entsprechenden bereits bekannten Ausmauerung.Should repairs of the floor be necessary despite the higher wear resistance, then repairing or replacing the ramming mass in the central floor area is considerably less expensive than repairing a corresponding, already known brick lining.

In einfacher Weise können Spüleinrichtungen, wie sie zum Homogenisieren der Schmelze (z.B. mit Stickstoff oder Argon) Verwendung finden, in einer Form im mittleren Herdbereich in die Stampfmasse eingebettet werden. Vorteilhafterweise sollten diese Einrichtungen ebenfalls aus nichtleitendem feuerfesten Material bestehen. Das Einbringen dieser Homogenisierungsmittel in der Mitte des Schmelzbades wirkt sich besonders günstig auf ihre Wirkung aus.In a simple manner, flushing devices, such as they are used to homogenize the melt (eg with nitrogen or argon), are embedded in a mold in the middle of the hearth in the ramming mass. Advantageously, these devices should also consist of non-conductive refractory material. The introduction of these homogenizing agents in the middle of the melting bath has a particularly favorable effect on their effect.

Dadurch, daß der Übergang zwischen der elektrisch leitenden ff-Ausmauerung und dem aus Graphitsteinen bestehenden ringförmigen Teil miteinander verschränkt ausgeführt sind, ist ein guter Stromübergang nach wie vor gewährleistet.Due to the fact that the transition between the electrically conductive ff-brick lining and the annular part made of graphite stones is interlocked, a good current transfer is still guaranteed.

Nachfolgend soll die Erfindung anhand eines Ausführungsbeispieles näher erläutert werden.The invention will be explained in more detail below using an exemplary embodiment.

In Fig. 1 ist ein Längsschnitt durch den erfindungsgemäßen Gleichstrom-Lichtbogenofen dargestellt.1 shows a longitudinal section through the direct-current arc furnace according to the invention.

Der Lichtbogenofen weist einen ringförmigen, aus Kupfer bestehenden Stromleiter 1, der einen Teil der Anode bildet, auf. Die Kathode 2 befindet sich zentrisch oberhalb der Schmelze. Auf dem aus vorzugsweise Stahl bestehenden Bodenteil ist eine feuerfeste isolierende Ausmauerung 7 vorgesehen. Direkt an dem als Kupferring ausgebildeten Stromleiter 1 ist ein ringförmiger Teil der Ausmauerung, der aus Graphitsteinen 3 besteht, in direkter elektrisch leitender Verbindung mit dem Stromleiter 1 vorgesehen. An diesen ringförmigen Teil aus Graphitsteinen 3 schließt sich ein weiterer Teil der Ausmauerung, der aus elektrisch leitendem ff-Material 4 besteht, an. Beide Bereiche sind miteinander verschränkt. Der Bereich der Ausmauerung, der aus elektrisch leitendem ff-Material 4 besteht, ist ebenfalls ringförmig ausgeführt. Dieser Bereich besteht vorzugsweise aus Karbon-Magnesit-Steinen.The arc furnace has an annular copper conductor 1, which forms part of the anode. The cathode 2 is located centrally above the melt. A fireproof insulating lining 7 is provided on the base part, which is preferably made of steel. An annular part of the lining, which consists of graphite stones 3, is provided directly on the current conductor 1, which is designed as a copper ring, in a direct electrically conductive connection with the current conductor 1. At this annular part made of graphite stones 3 another part of the Brick lining, which consists of electrically conductive ff material 4. Both areas are interlinked. The area of the brickwork, which consists of electrically conductive ff material 4, is also designed in a ring. This area is preferably made of carbon-magnesite stones.

Im Mittelbereich des Herdes, der mit der Schmelze in direkten Kontakt kommt, ist eine Stampfmasse 5, die vorzugsweise hauptsächlich aus Magnesit besteht, eingebracht. Durch verzahnte Ausführung der elektrisch leitenden ff-Ausmauerung 4 in Richtung des mittleren Herdbereiches, der durch die monolithische Stampfmasse 5 gebildet wird, kommt es zur innigen Verbindung beider Bereiche. Gegebenenfalls können hier noch isolierende Steine als Übergang eingefügt werden, die wegen ihres thermischen Verhaltens die Verbindung noch verbessern. In Zusammenhang mit der Sinterung des als Stampfmasse verwendeten Magnesits wird die Penetration von Stahl in diesem kritischen Übergangsbereich verhindert.In the central area of the hearth, which comes into direct contact with the melt, a ramming mass 5, which preferably consists mainly of magnesite, is introduced. By interlocking the electrically conductive ff-lining 4 in the direction of the central hearth area, which is formed by the monolithic ramming mass 5, there is an intimate connection of the two areas. If necessary, insulating stones can be inserted as a transition, which improve the connection due to their thermal behavior. In connection with the sintering of the magnesite used as ramming mass, the penetration of steel in this critical transition area is prevented.

In einer weiteren Variante kann im unteren Bodenbereich, dort, wo die monolithische Stampfmasse angeordnet ist, auf die untere feuerfeste isolierende Ausmauerung 7 verzichtet werden.In a further variant, the lower refractory insulating lining 7 can be dispensed with in the lower floor area, where the monolithic ramming mass is arranged.

Außerdem ist es möglich, wie nicht in der Figur dargestellt, Leitungen im mittleren Herdbereich vorzusehen, die in die Stampfmasse eingebettet sind und durch die z.B. Stickstoff oder Argon für die Homogenisierung der Schmelze zugeführt werden können. Diese Leitungen sollten ebenfalls aus nichtleitendem und feuerfestem Material bestehen.In addition, it is possible, as not shown in the figure, to provide lines in the middle of the hearth area which are embedded in the ramming mass and through which, for example, nitrogen or argon can be supplied for the homogenization of the melt. These lines should also be made of non-conductive and refractory material.

In der einfacheren Ausführungsform ohne diese Spüleinrichtungen kann es im Havariefalle, d.h. bei Zerstörung des Herdbereiches, zu keiner Gefährdung kommen, da im Bodenbereich keine zusätzlichen Einrichtungen vorhanden sind, die für den Betrieb des Ofens erforderlich sind.In the simpler embodiment without these flushing devices, in the event of an accident, i.e. in the event of the stove area being destroyed, there is no danger since there are no additional devices in the floor area that are necessary for the operation of the stove.

Bei einem Außendurchmesser des Ofens von 5,2 m ist die Ausdehnung des mittleren Herdbereiches, der durch eine monolithische Stampfmasse 5 gebildet wird, in seinem Durchmesser 2 m, soll jedoch mindestens 20 % des Gesamtaußendurchmessers ausfüllen.With an outer diameter of the furnace of 5.2 m, the extent of the central region of the hearth, which is formed by a monolithic ramming mass 5, is 2 m in diameter, but should fill at least 20% of the total outer diameter.

Claims (8)

  1. Lining for a direct-current arc furnace, providing at least a portion of the furnace area which accommodates the molten mass (8) internally with an electrically conductive fireproof lining and with an external annular current conductor (1) as a counter-pole of the top electrode (2) which protrudes centrally into the furnace, characterised in that
    the entire bottom area is covered by a fireproof insulating lining (7),
    this lining is in the outer radial wall area of the furnace fitted with a lining of graphite stones (3),
    the latter is adjoined in the radially inward direction by a circular zone of an electrically conductive fireproof lining (4),
    the middle bottom area above the insulating lining (7) is formed by a monolithic ramming compound (5), and
    the material of the furnace wall above the graphite-stone lining (3) substantially corresponds with that of the insulating lining (7) above the hearth bottom.
  2. Lining according to claim 1, characterised in that the monolithic ramming compound (5) is at least substantially composed of magnesite.
  3. Lining according to claim 1 and 2, characterised in that the graphite stones (3) which form the annular portion of the bottom lining are in direct contact with the current conductor (1).
  4. Lining according to claim 1 to 3, characterised in that the electrically conducting fireproof lining (4) extends in a ragged manner into the middle hearth area which is composed of a ramming compound (5).
  5. Lining according to claim 1 to 4, characterised in that insulating stones are arranged in the transitional area between the electrically conductive fireproof lining (4) and the monolithic ramming compound (5).
  6. Lining according to claim 1 to 5, characterised in that the hearth area which is composed of graphite stones (3) and the electrically conducting fireproof lining (4) are crossed/toothed relative to each other.
  7. Lining according to claim 1 to 6, characterised in that pipes for feeding homogenizing means into the melt are embedded in the middle hearth area which is composed of a monolithic ramming compound (5).
  8. Lining according to claim 1 to 7, characterised in that the diameter of the middle hearth area which is composed of monolithic ramming compound (5) covers at least 20% of the entire furnace diameter.
EP92113481A 1991-08-09 1992-08-07 Lining for a direct-current arc furnace Expired - Lifetime EP0530534B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US743146 1991-08-09
US07/743,146 US5199043A (en) 1991-08-09 1991-08-09 Lining for a direct-current electric arc furnace

Publications (2)

Publication Number Publication Date
EP0530534A1 EP0530534A1 (en) 1993-03-10
EP0530534B1 true EP0530534B1 (en) 1994-07-20

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EP92113481A Expired - Lifetime EP0530534B1 (en) 1991-08-09 1992-08-07 Lining for a direct-current arc furnace

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US (1) US5199043A (en)
EP (1) EP0530534B1 (en)
JP (1) JP2530083B2 (en)
KR (1) KR100259126B1 (en)
AT (1) ATE108974T1 (en)
AU (1) AU656395B2 (en)
CA (1) CA2070197C (en)
DE (1) DE59200296D1 (en)
ES (1) ES2056681T3 (en)
RU (1) RU2049297C1 (en)
TR (1) TR26545A (en)
ZA (1) ZA925925B (en)

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KR102183485B1 (en) * 2020-07-30 2020-11-26 주식회사 엔티에스 Method of manufacturing heat-radiating sheets by using wasted graphite
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CA2070197C (en) 1997-12-30
RU2049297C1 (en) 1995-11-27
AU2083992A (en) 1993-02-11
JPH05203361A (en) 1993-08-10
US5199043A (en) 1993-03-30
KR930005506A (en) 1993-03-23
DE59200296D1 (en) 1994-08-25
JP2530083B2 (en) 1996-09-04
ES2056681T3 (en) 1994-10-01
TR26545A (en) 1995-03-15
AU656395B2 (en) 1995-02-02
ATE108974T1 (en) 1994-08-15
ZA925925B (en) 1993-04-28
CA2070197A1 (en) 1993-02-10
KR100259126B1 (en) 2000-06-15
EP0530534A1 (en) 1993-03-10

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